[Bug] Shaded ball disappears in reading mode

[ajpower]

The following example renders a red sphere with shading

\begin{document}
\begin{tikzpicture}
    \shade[ball color=red, opacity=0.4] (0,0) circle (2cm);
\end{tikzpicture}
\end{document}

However, the shading vanishes when the note is reading mode:

In general, objects with the ball do not render correctly in reading mode.